“They had built those additional explosives, and we know they had the capacity to carry out the attacks,” said Bloomberg. “If, God forbid, they had arrived in New York City and gone to Times Square, one thing’s for sure, they would have seen an enormous police presence…[But] we don’t know if we would have been able to stop the terrorists, had they arrived here from Boston, we’re just thankful we didn’t have to find out that answer.”

Kelly said Dzhokhar Tsarnaev initially told FBI interrogators that they were going to New York City to “party” but later revealed that they “spontaneously” decided that Times Square would be their next target.

The brothers’ plan was hatched shortly after they carjacked a Mercedes SUV following the killing of an MIT police officer in Cambridge last Thursday night. The brothers had even loaded their remaining explosive devices – 6 in all, including a pressure cooker bomb similar to the ones used in the marathon bombings as well as pipe bombs – onto the hijacked vehicle.

“That plan, however, fell apart when they realized that the vehicle that they hijacked was low on gas and ordered the driver to stop at a nearby gas station,” said Kelly.

The duo forced their carjacking victim, a Chinese man, to pull over to a gas station on Memorial Drive where they could refuel.

“The driver used the opportunity to escape and call the police. That eventually led to the shootout in Watertown where the older brother [Tamerlan Tsarnaev] was killed in an exchange of gunfire with the police,” said Kelly.

Although Dzhokhar Tsarnaev managed to escape, sparking a massive manhunt in Watertown, he was later discovered hiding inside a boat behind a house on Franklin Street and captured alive. Dzhokhar Tsarnaev suffered several gunshot wounds and was taken to Beth Israel Deaconess Medical Center; his condition was upgraded from serious to fair Tuesday.

“We don’t know if those visits were related in any way to what he described as the brothers’ spontaneous decision to target Times Square. The NYPD Intelligence Division is actively investigating to determine Dzhokhar movements in New York City, as well as who he might have been with here,” said Kelly.